Dynamic Analysis of a 3-D Frame-Membrane Lunar Structure Subjected to Impact

A three-dimensional (3-D) frame-membrane structure covered with regolith shielding and pressurized internally has been proposed as a possible lunar habitat. This paper presents results from the dynamic impact analysis of the structure using nonlinear (large deformation) finite element technique. Results are presented taking into account the effect of the added mass of regolith and stress stiffening due to applied internal pressurization load. The impact load is considered arising from a moving object/debris/projectile hitting a membrane panel of the structure. The results show that both pressurization and added mass affect the displacement and stress response of the structure under the impact load. At the membrane node, the internal pressurization (prestressing) has greater effects to reduce the amplitude of oscillation of the vertical displacement in the case of without the added regolith mass than that in the case of with the added regolith mass. However, for the frame member nodes, when there was no added mass of regolith the amplitude of displacement seem to reduce slightly or remain the same due to pressurization. However, the effect due to pressurization is observed to be just the opposite (i.e. the displacement amplitude increased) when there was added mass of regolith.